GroupBy key
GroupBy key
Applies to Stream[Tuple2[K,V]]
the parallelism for this operation
the new KV stream
Sum the value of the tuples
Sum the value of the tuples
Apply to Stream[Tuple2[K,V]], V must be of type Number
For input (key, value1), (key, value2), will generate (key, value1 + value2)
the numeric operations
the sum stream